Cresse A D, Hulbert S H, Brown W E, Lucas J R, Bennetzen J L
Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
Genetics. 1995 May;140(1):315-24. doi: 10.1093/genetics/140.1.315.
The Mutator transposable element system of maize was originally identified through its induction of mutations at an exceptionally high frequency and at a wide variety of loci. The Mu1 subfamily of transposable elements within this system are responsible for the majority of Mutator-induced mutations. Mu 1-related elements were isolated from active Mutator plants and their flanking DNA was characterized. Sequence analyses revealed perfect nine base target duplications directly flanking the insert for 13 of the 14 elements studied. Hybridizational studies indicated that Mu1-like elements insert primarily into regions of the maize genome that are of low copy number. This preferential selection of low copy number DNA as targets for Mu element insertion was not directed by any specific secondary structure(s) that could be detected in this study, but the 9-bp target duplications exhibited a discernibly higher than random match with the consensus sequence 5'-G-T-T-G-G/C-A-G-G/A-G-3'.
玉米的增变基因转座元件系统最初是通过其在极高频率下和在各种各样的基因座上诱导突变而被鉴定出来的。该系统内的转座元件Mu1亚家族是大多数增变基因诱导突变的原因。从活跃的增变基因植物中分离出了与Mu1相关的元件，并对其侧翼DNA进行了表征。序列分析显示，在所研究的14个元件中的13个元件中，插入片段的直接侧翼存在完美的9个碱基的靶标重复序列。杂交研究表明，类Mu1元件主要插入玉米基因组中低拷贝数的区域。作为Mu元件插入靶标的低拷贝数DNA的这种优先选择，并非由本研究中能够检测到的任何特定二级结构所引导，但是9碱基对的靶标重复序列与共有序列5'-G-T-T-G-G/C-A-G-G/A-G-3'的匹配明显高于随机水平。
